WESTERN TANAGER. Piranga ludoviciana (Wilson)

Field characters.—Between Robin and Junco in size. Sexes different. Male: Head red; wings, upper back, and tail, black; rest of body plain lemon yellow. Female: Dull yellowish brown (sometimes greenish in effect) on upper surface; dull yellowish white beneath. Both sexes notably deliberate in all movements, the opposite of nervous. Voice: Song of male a hoarse drawling note, cher'-wer, repeated three to many times in rather rapid succession with but slight changes in intonation; call note a hoarse cher'-tig, or chee'-tik, or prit'-it, frequently repeated.

Occurrence.—Common summer visitant in Transition and Canadian zones on west slope of Sierra Nevada; sparingly represented on east slope. Observed by us from 3 miles east of Coulterville and from El Portal eastward to Tenaya Lake and Merced Lake; also in vicinity of Mono Lake. Passes through lowland and foothill country on west side (Snelling, Lagrange, Pleasant Valley, Coulterville, etc.) in spring migration. Keeps to open forest during nesting season. In pairs at nesting time; otherwise seen singly except as small flocks may be formed in early fall, before departure.

The Western Tanager, often called Louisiana Tanager in books, is among the most conspicuous birds of the Yosemite fauna, combining as it does brilliant coloration and unfearful disposition with a preference for open portions of the forest. The male wears a livery of bright yellow, with a red head and black wings and tail, while his mate is garbed in dull yellow and greenish brown. The species is so well represented on the floor of Yosemite Valley and in the Canadian Zone forest on the slopes adjacent that the tanager will usually be one of the first birds to gain the visitor's attention after his arrival within the Park.

The northward passage of the tanagers through the lowland and foothill districts of California in late spring constitutes one of the most conspicuous migratory movements among our birds. The brilliant coloration of the males and the distinctive call note of the species, so different from that of any of the resident low zone birds, together serve to focus the attention of even casual observers on this seasonal movement. Near Lagrange on May 7, 1919, five or more Western Tanagers were seen during an hour and a half in the blue-oak belt. On the slopes of Penon Blanco the birds were moving through the greasewood chaparral on May 9, 1919, and near Coulterville on the following day transient tanagers were notably numerous. In 1915, at Pleasant Valley, about 10 migrants were seen during a 5-hour census on May 24, and a single one was noted there on May 30, while two were observed at Snelling on May 29, and one near Coulterville on May 31, of the same year. East of the Sierras, at Walker Lake, one tanager was seen May 9, 1916. Thus the spring migration is known to occupy much of the month of May.

During the summer season tanagers inhabit mainly the more open portions of the forest. Their preference in Yosemite Valley seems to be for black oaks and incense cedars, although they are seen in most other trees as well. Numerically, the tanager is not an abundant species. Our censuses show on the average one or two birds to an hour of observation. In some localities the number is larger, but never up to that of the robin or of the chipping sparrow. Of course there is a sudden doubling or trebling of the tanager population in July when the broods of young leave the nest. In late August, when cascara and other berry-producing shrubs are fruiting, the tanagers often assemble in flocks numbering under a dozen individuals, and this gathering of the birds is likely to give an observer the impression of still further increase in numbers. It is not unlikely that some of the tanagers from the Canadian Zone drop down into Yosemite Valley before all depart southward.

The Western Tanagers remain in the mountains of the Yosemite region until some time in September. Single individuals were observed by us at Walker Lake on September 13 and 15, 1915, and small numbers were noted in Yosemite Valley up until September 5 of the same year. In 1920 tanagers were observed regularly until the middle of September; the last individual was noted on September 28 (C. W. Michael, MS). All are gone certainly before the first of October.

The vocabulary of the Western Tanager is not elaborate. The song is but little more than a repetition of notes like those which constitute the call. There is a peculiar droning quality to the utterances which makes them readily distinguishable from those of other birds. Once learned, the notes are the best clue to the presence of tanagers, either when they are on their nesting grounds in the mountains or when they are passing in migration through the lowland country. The call note is a drawling, two-syllabled prit-it or pree-tert, sometimes changed to a more abrupt cher-tig, or chee-tik. The song consists of a rapid repetition of the syllables cher'-wer, sometimes modified to chee'-wer, or chir'-rup, or zer'-wer, or zee'-wer. The song season of the tanagers lasts from the time of their arrival on their nesting grounds until some time in July. The tanager sings at all hours of the day. It begins almost as early as the wood pewee and the robin. At El Portal on May 31, 1915, our notes record the tanager as the most insistent singer in the morning chorus there. At least four were within hearing of the hotel at 4:30 A.M. They were also singing until late dusk of evening.

The Western Tanager is a bird of deliberate movement; indeed it might even be characterized as apathetic in temperament. In perching, foraging, or flying, its demeanor is ever the same; this sedateness of manner seems never to be lost, even under stress of sudden surprise. It may be that this mode of behavior is related to the male's brilliant coloration. In a bird the size of a tanager showing large areas of bright color, quick movements like those of a warbler would almost surely serve to draw attention. But by adopting a slow deliberate type of action the tanager is much more likely to escape observation, despite its bright coloration. Frequently we have gazed at a tree for some moments before realizing that a Western Tanager was sitting there in plain sight before us. The fact is, that the bird had escaped detection. Whether this is to be explained on the basis of protective, concealing, or disruptive coloration is a matter for speculation. However this may be, the factor of the bird's quietude seems to us to play an important rôle in its protection.

We learned of no case of a tanager being beset by any sort of enemy. Only one instance of death from natural cause came to our notice. This was at Mono Lake Post Office on May 24, 1916, following a night when snow fell. A pair of tanagers that had roosted in an old building were found dead and frozen in the morning, but whether the cold itself was the direct cause of death was not determined.

The Western Tanagers begin nesting activities soon after they arrive in the Yosemite region. Little or nothing in the way of courting, other than the persistent singing of the males, has been noticed of these birds. On May 23 (1919) in Yosemite Valley a female was first seen at work on a nest, and immediately after that date quite a number of other females were observed gathering material, or building. Nest construction may be looked for with confidence regularly during the last week of May; in 1911 one female was seen building on May 26 and another, in 1915, on May 31.

The work of nest construction is carried on entirely by the female, and even when searching for material she is rarely if ever accompanied by her mate. She employs no subterfuge, but usually gathers the material on the ground in the near vicinity and then flies directly to the nest site. The nest is located in trees and placed well above the ground, supported by several small diverging twigs toward the end of some horizontal branch. The height of the nests seen by us was about 20 to 25 feet, although one was estimated to be 60 feet above the ground. Another, situated in a rose bush (an exception to the rule above given) was within 10 feet of the earth. The nests are loosely constructed and flattish, the height being about half the breadth. Pine needles, long crinkly rootlets, and dried grasses are used as building materials; these are put together in lattice-work fashion, so that from below it is often possible to see light through the interstices.

Prior to the time that incubation commences, the members of a pair are seen often together; but after the female begins to sit the two birds forage in company only for brief periods during the early morning and evening hours. Through the day the male goes about by himself, foraging on the ground or singing somewhere well up in the trees. He evidently takes little or no part in the family duties until the eggs hatch, but after that event he is almost as busy as his mate in caring for the brood; he takes food to the nest at frequent intervals through the day. The young appear abroad in July. The juvenal plumage, which is much like that of the parent female save for obscure streaking on the under surface, seems to be worn only while the young birds are in the nest. By the time they are old enough to leave, or at least very shortly thereafter, they have molted and are then indistinguishable from the adult female.

After the breeding season the tanagers do not wander to any appreciable degree up into the higher zones. Only one individual, a male, was observed by us in the Hudsonian Zone. He was seen near the Soda Springs on Tuolumne Meadows on July 13, 1915.

Tanagers in summer forage to a large extent in the trees for insects, but some of their provender is apparently gathered also on the ground. In late summer and early fall they turn to a vegetable diet and feed upon berries of several kinds which are usually abundant on the floor of Yosemite Valley in that season. Mr. Joseph Mailliard (1918, p. 14) says of the Western Tanagers seen in the Valley in 1917:

They were occasionally seen in August, but grew more and more numerous, evidently gathering from far and wide, as the berries of the 'cascara sagrada' [= Rhamnus californicus] became ripe, upon which they regaled themselves seemingly almost to the point of bursting. At the foot of a cedar tree close to the writer's tent in Camp Curry was one of these bushes covered with fruit, near which many people passed in the course of the day along one of the camp avenues. Almost touching the bush was a round table three or four feet in diameter, and beside it a rustic rocking chair. In spite of people passing, tanagers would drop down from the cedar tree, even when the chair was occupied, and if the occupant kept still and was apparently indifferent to their actions, would go so far as to alight on the table.